"The technical information gives some ideas about the size
of the battery pack for the Yuan-class of diesel-electric submarines to be
equipped with an air-independent propulsion system (AIP) powered from large battery
banks.

The battery pack consists of 960 pcs of the
WB-LYP10000AHA cells making the total
energy of 31 MWh. The lithium battery is saving some 260 tons of weight against
the original lead-acid pack. With this pack the Yuan-class (B-class) diesel-electric
submarine can drive 3,300 nautical miles or it can stay under water for 800
hours (33 days). This indicates the average onboard consumption of the
submarine when not moving is some 38kW/h."

The first batch of Yuans are widely thought to have standard lead-acid batteries and Stirling AIP. The "B-class" of the Yuans may mean the second batch/Mark 2 Yuans that have LIBs instead of (or as well as) the Stirling AIP. A December 2015 US report to Congress (page 91) states "The YUAN SSP is China’s most modern conventionally powered submarine. Eight are
currently in service, with as many as 12 more anticipated." So the 12 may be the second batch - maybe with LIBs?

As can be seen below China is also marketing submarine capable WB-LYP10000AHA batteries to Russia.

The specific Lithium-ion in the battery is LiFeYPO4 (hence the "LYP"). China's near economically exclusive access to Yttrium (Y) means China has a major advantage in offering Yttrium in its manufactured products. For battery experts the advantage of LiFeYPO4 over plain LiFePO4 is "additional Yttrium at the cathode of the LiFeYPO4 cells speeds up
electron transfer especially at cold temperatures". This would be advantageous for Chinese Yuans and Russian submarines starting their engines at sub-zero northern winter temperatures and then contuing through the cold saltwater of winter seas (down to minus 2 Celsius before the water ices up).

Pete,Since the Chinese statement is 38KWh when not moving, this points to China using an AIP solution with Lithium batteries. The AIP Stirling plant is dedicated to propulsive needs while the lithium batteries address combat management and other hotel needs. This hybrid solution may be necessary as I do not know if China can produce a 75KW Stirling engine or not? Theirs may be less efficient but this is speculative of my part.KQN

I find performance measures batteries difficult, terminology and all. I'll need to start from https://en.wikipedia.org/wiki/Lead%E2%80%93acid_battery and https://www.youtube.com/watch?v=cxkVxi9P0EA to get up to speed.

Some comparison of likely dimensions of a Japanese submarine's GS Yuasa LIBs "total capacity per group module is 33.9KWh" is at http://gentleseas.blogspot.com.au/2015/10/japans-lithium-ion-battery-advantage.html

Yes China appears much more into LIBs for submarine than previously assumed.

Re " I do not know if China can produce a 75KW Stirling engine or not?"

http://www.china-defense-mashup.com/stirling-engine-used-in-pla-newest-conventional-submarine.html indicates that China may have developed Stirling in parallel with Sweden and/or used some reverse engineering. It appears China has developed Stirling AIP with 75KW performance .

So http://www.china-defense-mashup.com/stirling-engine-used-in-pla-newest-conventional-submarine.html indicates:

"In March 2007, Science & Technology Daily, One of China official newspapers, publish a news story, which showed that China has used Stirling Engine as AIP power for PLA navy newest Type 039A conventional Submarines.

...For 10 years (from 1991 to 2000), No.711 Research Institute has made the most excellent achievements. In 1998, Jin Donghan and his team made China’s first theoretic demonstrating Stirling Engine, which power is 75KW. Unlike ROK and Australia, China has solved related technological and engineering difficulties in Stirling Engine. In 2002, Jin Donghan’s team worked out an engineering demonstrator. After 20,000 hours’ testing, China’s own Stirling Engine was installed in China’s Type 039A submarine in 2004.

China’s fruition in Stirling Engine can not be realized without substantial investment for years. From 1991 to 1996, the annual investment is only 70,000 RMB and from 2000 to 2005, the number changed to 10 million RMB."

1. Russia doesn't seem to have alot of money for its conventional submarine program. China's LIBs for submarine have expensive? Lithium and rarer Yttrium. So these LIBs may be expensive for Russia to develop.

2. Problems in 1 may be resplved if LIBs were a joint Russian-Chinese venture and China accepted bartered Russian technology (instead of low value Russian rubles). So scenario 2 may be a goer.

Its still unclear whether Russia will finally shelve the domestic "Lada" brand and only concentrate on the domestic "Kalina" brand. In either case the export version may or may not carry the brand name "Amur".

An Improved Kilo is a large 2,350 ton (surfaced) submarine so that would be alot of expensive LIBs.

The proposed average onboard consumption of the submarine (38kW/h) when not moving is too low and unrealistic. It should be 120-150kW/h. Simulation by submarine expert shows submarine with LABs can stay 100h-200h. As capacity of WB-LYP10000AHA cell is twice larger than that of LABs, Yuan-class (B-class) can move for 7 days at 4knot and stay for 2weeksas, I think.

Low speed performance of Type 212A and Soryu Mark 2s with increased LIBs are as follows - 3,600 nm over 30 days at 5kt/h for German Type 212A fuel cell AIP based on demonstration and - 1,400 nm over 14 days at 4kh/h for Soryu Mark 2s using LIBs in my opinion.

We can judge that B-class Yuans does not equip the Stirling AIP by comparison of B-Yanun with Soryu in terms of number and size of WB-LYP10000AHA cells. Total floor area of WB-LYP10000AHA cells with vertically tandem arrangement is 1.4 times larger than that of LIBs of current Soryu. Yuan is smaller than Soryu. The Stirling AIP generators need huge liquid oxygen (LOX) tanks. According to increased floor area of cells, smaller submarine size and huge LOX tanks, B-class Yuans cannot equip the Stiring AIP.

In that time, as I did not notice existence of two important documents [1, 2] and other information, I overestimated low speed performance of Soryu MK 2. I recalculated submerged period of Soryu MK2 at 4kt/h, which is 10-14days. This calculation is very rough and various factors are neglected due to lack of additional information, but better than no calculation.

[1] “Submarine Power and Propulsion- Trends and Opportunities” by John Buckingham et al, Paper on Submarine Power and Propulsion Presented at Pacific 2008 in Sydney, Australia. “Figure 2 - Estimated Submerged Speed v Endurance for a Range of SSKs”[2]”General rules of electric propulsion system for submarine – Part II: Submarine equipped with AC main motors” This Ministry of Defense Standard specifies propulsion system of Soryu.

This underlines that the whole issue of LIBs and a submarines electrical requirements are very complex.

A November 2015 newspaper report is that there may be shortage of Australian Defence Department engineers with expertise in "next generation batteries" http://gentleseas.blogspot.com.au/2015/11/buying-subs-australian-dods-disrupted.html

Submarine Matters

Director, Submarine Matters International. I analyse international trends, technical and political - mainly on submarines, sometimes on surface ships, aircraft and missiles. This website started in 2007. I have a Masters Degree (International Relations) High Distinction average. The best way to navigate this site is to put a keyword in the search box top left corner.